pschum

I posted this in other Tech areas too.

I was hoping someone could tell from the attached pictures what may have caused the ECU burnout.

I checked all the fuses were & are good and I put in a new Main Relay before I found out the ECU was the problem. The car would not start, no spark or power to the fuel pump so I thought it was the Main Relay.

It looks like it's the brownish capacitor and it's in the area of the "B" connector.

Thanks,

Pete

Relic1

welcome to capacitor death, growingly common with our aging ECUs. (brown cap leaks and causes this)
replace the cap, repair any traces eaten away and reuse.
I've repaired several like this or worse.

joelmatt89

yeah like he said it could have just been a bad cap. I have actually blown this exact same cap before and after replacing the ecu i haven't had a single problem since.

pschum

Thanks Relic1 & Joe,

I'm hoping all si okay and it's just a leak issue. I'll also try to do some checks as others suggested.

I agree the ECU is almost worth more than the car. It's my Marine son's girlfriends car and I'm trying to help her/them keep it going.

I checked everywhere for a ECU used they wanted $125 with no refund.
So I went on line and the range for rebuilt with core is $240.00 to almost $400.

If you guys have a good source please let me know.

Thanks again Guys

WeakSauce92

125 seems normal for my area but no refund sucks but I guess I can understand.

joelmatt89

It looks like a p28 so yeah around that $125 range is probably about right the best deals you will find though will be on this site i the marketplace I would check there first

AGENT_47

EBAY

I got my new "used" P28 from a vendor there and my car has never run better.

Don't worry in this age range fried ECUs are normal

Is it an auto or manual?

PrOxY_KiLLeR

That exact same thing happened to my ECU and they told me it could not be fixed, and my mechanic gave me a different one a bigger one. And it turns on like a new car and runs great but it has kinda like a whistle in the engine. That isn't normal... Any help on what could it be?

94EG8

It was at least originally in an automatic.

AGENT_47

why did he give you a "different one" and "bigger"?


he should just have replaced it with the exact one you had before

I had a p28 auto and replaced it with a p28 auto

AGENT_47

well this vendor sold me my p28 ECU and it works fine, I can vouch for him

sad though he doesn't offer returns

but mine worked great , I left a comment under my name agentxx47
,you can see I purchased one

My Honda dealership actually referred him

http://shop.ebay.com/habibsitr/m.htm...&_trksid=p3686

pschum

Thanks to all, appreciate the help. Agent47 I'll check that site out thanks.

Pete

pschum

AGENT_47,

That site looks good.

A question to all. The number that 's on ours is 37820P28A51

Can other P28 numbers be used? Such as an A50.

Thanks

Pete

94EG8

You can use another revision. The breakdown for the numbers breaks down as follows:

37820 -> Honda's part number for an ECU, all Honda ECUs start with this number.
P28 -> loosely identifies car/trim level/engine, in this case it designates that the car uses a D16Z6 engine
A -> Country code, in this case USA
5 -> Identifies the transmission type, 5 & 9 are typically automatic, 0 is typically a 5 speed
1 -> revision, this doesn't make much difference, any revision will work.

AGENT_47

make sure you get a manual ECU if you have a manual , you can convert the auto ECUs to manual by swapping transistors though

ask the seller he/she may be able to do it for you

94EG8

I'm pretty sure the OP has an automatic, its pretty simple to convert an automatic ECU to manual, the opposite isn't true though, 5 speed ECUs just don't have the extra components to control the automatic transmission.

pschum

Thanks guys. I'm going to bid on the 50 then.

Our car is an automatic so if I'm reading right the 37820P28A50 should work.

God I hope so this has been a real odeal.

Thanks to all for all your help this web site is awesome and all you guys are great.

Pete

94EG8

A50 will work fine.

pschum

Thank you.

DJohn916

ECU P06
93 HONDA CIVIC DX
I find the c14 squirted its contents out and and replace it for one with the same value put ecu back into the car and worked fine for few hrs then problem persisted...
I removed ECU again and find out that cap 19 was damaged too
can't find 33uF (33 microfarads) capacitors anywhere even in my junk green boards so I replace with a closest value I find 47uF
it will affect on something?

crazyhouse2011

TomCat39

Not sure what your voltage was on your 33uF cap. I also came across a 100v version but the leads were on each size and the cap might be a bit larger.

As for the circuit, it's hard to say. It all depends on what the cap is supposed to do in the circuit. If it is for filtering frequencies then yes it will affect how the circuit operates but depending on why it's filtering will really be the clincher. If it's more for rectifier type filtering, probably won't be as much of an affect. And if it's to maintain a DC voltage, then it should have no affect at all.

It all depends on what the capacitor is doing for the circuit. I don't believe the FSM has the schematics of the ECU.

DJohn916

they all are rated at 35v max but since the power supply its 12v you can use from 18v to 50+v it doesn't matter cause is the maximum voltage allowed for the capacitor...
the important part is the uF...
I have circuit knowledge but Is on audio amps...
I did post my results just in case someone professional on ECU's come across it and give me a clear answer

TomCat39

If what they used is rated 35v then I would not go under that. If anything I would go above just for added strength. It's the spikes of switching that kill electronics. It's also why they don't use double ratings components than what the circuit operates at. It's called planned obsolescence or better known as job security. It works well, the cap popped. An 18v would just pop sooner. The 50v will probably last 35-45 years instead of 20.

I too have circuit knowledge being I was shooting for my associates degree in electronics back in the 90's.

The issue is that the schematics for the ECU's is not common property, so unless you sit down and build your own schematic by following the traces to the components and look up the IC chips etc etc (no fun, I've done it in the past), you can only speculate what the use is for.

Then again, you already know some of the typical uses of caps so already know that some uses a slight variance in capacitance won't have much affect and others it can significantly impact the circuit. For all you know, it could be to set an RC time constant and changing the capacitance will change timing thus adversely affecting how the engine runs.

The easiest way to tell is do the trace work for the capacitor and see what all it connects to and build the immediate surrounding schematic so you can see what type of circuit it's being used in.

Or even better, order the 33 microfarad capacitor 50v I found and pop it in so you know it's the same capacitance and don't have to fret knowing you are sticking to the designers design.

DJohn916

DJohn916 reply...
yeah that's true...
I'll go and look for at Fry's electronics...
I did use a 47uF cause I was trying to get my car running for the moment...
anyways my car performed way better but still not priming fuel pump or sending ground signal to pin #8 of the main relay after rain..
yesterday I followed all the wiring from the ignition switch all the way to the ECU and showed 12v all the way,
found 12v positive on pin A25, B1, D1...
some diagrams I found in the web shows B1 as ground but that's is incorrect for a P06 ECU
adjusted plugs with a needle and replaced all the brown capacitors
car being working fine since then I hope that was the fix
by the way, seems like Capacitor19 goes to pin D19